Safety closure

ABSTRACT

A childproof safety closure of two parts, one part having a skirt with internal screw threads to form a conventional screw cap closure, the second part being an overcap completely covering the threaded closure member and being freely rotatable in relationship thereto, said overcap having on its top a projecting stud and a similar shaped opening which serves as a key for unscrewing the inner closure member of another closure of similar construction.

United States Patent Birch [54] SAFETY CLOSURE [72] Inventor: Richard W.Birch, Macedonia Road, Kent, Conn. 06757 22 Filed: Feb. 1,1971 21Appl.No.: 111,197

[52] US. Cl ..215/9 [51] Int. Cl. ..A6lj l/00, 865d 55/02 [58] Field ofSearch ..215/9, 43 A, 46 R [56] References Cited UNITED STATES PATENTS3,138,277 6/1964 Milboume ..215/9 3,412,886 11/1968 Colella et a1..215/9 115] 3,684,115 51 Aug. 15,1972

Primary Examiner-George T. Hall Attorney-Eugene O. Retter, George W.Rauchfuss,

Jr. and Harvey W. Edelblute ABSTRACT 7 3 Claims, 7 Drawing lfi'guresPATENTED M18 15 m2 INVENTOR RICHARD W'YRLEY BIRCH Y i w ZAT ZZ m'romnzvlllfllllllllll lmmun IIIHIIIIIIII 'FIG.I

BACKGROUND OF THE INVENTION The increased use of highly potent drugs inthe home in recent years has created a demand for safety closures formedicine bottles and other containers which are difficult to open byyoung children who may obtain possession of such containers whileplaying. As a result, many different child-resistant safety closureshave been developed. One type of safety closure is characterized byhaving a conventional screw cap to close the bottle with an overcapwhich covers the screw cap and freely rotates over it so that turning ofthe outer cap will not result in turning the closure, except undercertain conditions. For example, the United States Pat. to Farago, No.3,027,035, is characterized by having an outer cap which can be defonnedby pressure on its skirts which can result in friction on the screw capclosure whereby the latter may be turned off of the bottle. While thiscap is quite simple in structure and inexpensive to make, it requiresthe application of a considerable amount of force on the skirt to createenough friction to loosen the screw cap closure. While very youngchildren cannot produce this amount of force to open the closure, it isalso true that older people, particularly those with arthritis of thehands, find it difficult to remove the closure.

Other safety closures which depend-upon a loosely fitting overcap may befound in the prior art. For example, in U. S. Pat. No. 3,428,201 to Boysthe friction necessary to turn the inner screw cap closure is developedby exerting downward pressure on the top of the cap. This type closureis also difficult to open by the elderly.

To avoid the necessity of applying pressure on a freely turningresilient outer cap to develop enough friction to turn the innerscrew-on type closure, structures have been devised in which a keyelement is used to engage the outer cap with the inner closure member sothat it may be removed. One such structure is shown in U. S. Pat. No.3,160,301 to Milbourne. Various other patented structures which employkeys to engage a of the safety closure;

loose overcap with an inner screw closure so that the latter may beturned have been issued. Note, for example, U. S. Pat. No. 3,485,402 toTunstall, U. S. Pat. No. 3,164,277 to Reading, and U. S. Pat. No.3,396,864 to Jones et al.

SUMMARY OF THE INVENTION The present invention is directed to a safetycap of unique construction which has advantages over the previouslydescribed safety caps of the prior art. It is simple in construction,inexpensive to make, and can be readily operated by elderly persons withweak hands, but is not likely to be operated by children and others whoare not able to understand the manner in which the screw cap closure maybe removed, particularly if they are not allowed access to anothersafety cap of identical construction which acts as a key. In brief, thestructure of the present invention includes a more or less conventionalthreaded screw cap closure having a recess on its upper surface and anovercap which fits over the screw closure and is freely rotatable withrespect thereto, but is so stiff that it cannot be deformed with normalpressure of ones fingers. The overcap is characterized by having anupstanding projection which serves as a key and a similarly configuredopening, or key hole, whereby the freely rotating overcap of one safetycap may serve as a key for turning the screw cap closure of another butidentical safety closure.

BRIEF DESCRIPTION OF THE DRAWING In order that the invention may be moreclearly understood, reference is made to the accompanying drawing, inwhich:

FIG. 1 is a vertical elevation of a bottle having the safety closure ofthe present invention in place;

FIG. 2 is a cross-section in elevation showing the safety closure of thepresent invention;

FIG. 3 is a top plan view of the screw cap closure part FIG. 4 is across-sectional view in elevation of the screw cap closure part of FIG.3;

FIG. 5 is a top plan view of the overcap portion of the closure of thepresent invention;

FIG. 6 is a cross-sectional view in elevation of the overcap of FIG. 5;and

FIG. 7 is an elevation, partly in section, showing two identical safetyclosures joined in position for removing the screw-type closure from theneck of a bottle.

DESCRIPTION OF A PREFERRED EMBODIMENT In FIG. I, the safety closure 1 ofthe invention is attached to the neck 2 of a bottle or other container3.

As shown in FIG. 2, the closure consists of an outer cap 4 and a screwclosure 5. This screw closure may have a conventional liner (not shown)if desired. It may be of any suitable material, but molded plastic ispreferred.

The screw cap closure is characterized by having a recessed portion 6 onits upper surface 7 as shown in FIGS. 3 and 4. The recessed portion mayvary in configuration but in a preferred embodiment it has an area,generally speaking, which can be designated as a truncated ellipse.

V The outer cap 4, as shown in FIGS. 5 and 6, is preferably molded froma relativelystiff but elastic plastic material and is characterized byhaving an inwardly extending lip 8 which may be expanded by pressure toslip over the outer surface of the inner cap 5.

' After the lip 8 is forced over the skirt of closure 5, it

will return to its normal diameter as shown in FIG. 2 and will lock theovercap in place over the screw closure element and hold it thereon sothat it cannot be removed without considerable effort. The outer cap 4has an inner wall diameter slightly greater than the outer diameter ofthe screw closure and will freely turn on the closure 5. The outer cap 4is of sufiicient rigidity that it cannot be made to frictionally engagethe inner cap 5 with any amount of pressure that could be placed upon itby a small child.

The outer cap 4 is also characterized by having an upwardly extendingstud 9 and an opening 10 of substantially the same configuration. Theupwardly extending portion 9 of the outer cap is slightly smaller thanthe opening 10 so that it may fit into the same opening of anotheridentical cap. Also, the height of the upwardly extending stud is suchthat it will pass through the opening in said other cap and extend intothe recessed space in its screw closure. The recess in the top of thescrew cap closure element is sufficiently large so as to permit entry ofthe upwardly extending portion of an overcap from an identical closurethrough opening into the recess. The larger the area of the recess, theless likelihood that the inner cap can be turned by an object other thanthe upwardly extending stud 9 of the overcap which acts as a key, aswill be explained.

As noted above, the area of the recess on the screw cap closure ispreferably ellipsoidal. Other area shapes may be used, except that itmust not be that of a circle concentric with the axis of the cap. Thedistance of the surface of the inner wall of the recess from the axis ofthe closure must be less at one point than the maximum distance of theouter wall of the upwardly extending stud from the vertical axis of theovercap. This relative configuration is necessary so that the upwardlyextending stud of the overcap of one closure will engage the inner wallof the recess of another screw closure at some point on its periphery asthey are turned with respect to each other. Thus, the upwardly extendingsection 9 may be circular instead of semi-ellipsoidal as shown in thedrawings, and the opening 10 may also be circular instead ofsemi-ellipsoidal and in such a case the stud and opening aresymmetrically located on opposite sides of the top of the overcap. Therecess 6 may be ellipsoidal or circular, as shown, if its center is notconcentric with the vertical axis of the closure cap.

To remove the screw closure and thus open the bottle so that thecontents may be removed, one safety closure of the present invention ispositioned top to top over another, as shown in FIG. 7, and by graspingthe outer sleeve of one of the closures between the fingers, the screwclosure of the safety cap must be turned off of the neck of the bottle.The screw closure may be replaced in the same manner.

As will be apparent, it is necessary to have two substantially identicalclosures in order to remove one from a bottle to which it may beattached. Obviously, it would be necessary to supply the buyer of thefirstpurchased bottle with an extra safety closure, or the purchaser maybe induced to buy two bottles with identical closures. Of course, afterthe first such purchase, the safety cap of one of the bottles may besaved and used for opening subsequently purchased bottles fitted withthe same type closure.

It will be obvious upon consideration of the structure that has beendescribed that coins, knife blades, screwdrivers, and other commonlyavailable objects which might serve as keys to engage the inner screwcap portion of the closure cannot be used to open the bottle as is thecase with some of the safety closures of the prior art. Only theupstanding element on another substantially identical closure will passthrough the opening 10 of the outer cap and engage the walls 11 of therecessed part of the screw closure whereby it may be turned off thethreads of the neck of the bottle with which it may be engaged.

What is claimed is:

1. A safety closure having in combination an inner ca losure me her andoverc member,

aid inner caia having azi cirt witi r internal threads and a flat tophaving a recess therein, the inner walls of the recess varying indistance from the vertical axis of said cap,

the overcap completely covering the outer surface of the inner cap andbeing freely rotatable with respect thereto,

means for preventing the overcap from being removed from the inner cap,

said overcap having on its top an upwardly extending stud and an openingof substantially the same configuration, both stud and opening beingsymmetrically located on opposite sides of the axis of said overcap, theheight of said stud being greater than the thickness of the top of saidovercap,

the inner wall of the recess of the threaded closure member being at onepoint a distance from the axis of the closure greater than that of theoutermost wall of the stud from the axis of the closure and at one pointbeing less than the outermost wall of said stud from the axis of saidclosure.

2. A safety closure in accordance with claim 1 in which the recess inthe top of the inner cap is ellipsoidal in configuration and thecross-sectional area of the upwardly extending stud on the overcap andthe area of the opening in the top of the overcap when taken togetherhave an ellipsoidal areaslightly smaller than the ellipsoidal area ofthe recess.

3. A safety closure in accordance with claim 1 in which the means forpreventing the overcap from being removed from the inner cap is aninwardly extending lip on the lower section of the skirt of the overcaphaving an internal diameter less than the external diameter of thethreaded closure member.

E STATES OFFICE CERTIFIC TE 0F CORRECTION Patent No. .5,68 i,l15 DatedAugust 5, 97

Inventor) Richard W. Birch it. is certified that error theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Coiumn 3, i ine 38, "must" shou'ld read may"; in the heading to theprinted specification 1 ines 1-2,

"Inventor; Richard W. Birch, Macedonia Road, Kent, Conn. 0675?" shouldread inventor: Richard W. Birch, Macedonia Road, Kent, Conn. 06757,assignor to Richardson-Merreii Inc., New York, i i.Y.

Signed and sealed this 1st day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. (3. MARSHALL DANN Attesting Officer Coxrmissio'nerof Patents

1. A safety closure having in combination an inner cap closure member and an overcap member, said inner cap having a skirt with internal threads and a flat top having a recess therein, the inner walls of the recess varying in distance from the vertical axis of said cap, the overcap completely covering the outer surface of the inner cap and being freely rotatable with respect thereto, means for preventing the overcap from being removed from the inner cap, said overcap having on its top an upwardly extending stud and an opening of substantially the same configuration, both stud and opening being symmetrically located on opposite sides of the axis of said overcap, the height of said stud being greater than the thickness of the top of said overcap, the inner wall of the recess of the threaded closure member being at one point a distance from the axis of the closure greater than that of the outermost wall of the stud from the axis of the closure and at one point being less than the outermost wall of said stud from the axis of said closure.
 2. A safety closure in accordance with claim 1 in which the recess in the top of the inner cap is ellipsoidal in configuration and the cross-sectional area of the upwardly extending stud on the overcap and the area of the opening in the top of the overcap when taken together have an ellipsoidal area slightly smaller than the ellipsoidal areA of the recess.
 3. A safety closure in accordance with claim 1 in which the means for preventing the overcap from being removed from the inner cap is an inwardly extending lip on the lower section of the skirt of the overcap having an internal diameter less than the external diameter of the threaded closure member. 